To examine the social and economic impacts of the next Grand Solar Minimum – See About

David Whitehouse Interviews Nicola Scafetta, a scientist at Duke University and at the Active Cavity Radiometer Solar Irradiance Monitor Lab which is associated with the NASA Jet Propulsion Laboratory in California, at the Global Warming Policy Foundation web site.

Scafetta claims that “at least 60% of the warming of the Earth observed since 1970 appears to be induced by natural cycles which are present in the solar system.” As his theory is controversial, Whitehouse asked him to outline it. For the near future Scafetta predicts a stabilisation of global temperature or cooling until 2030-2040.

Here is the money question, with the answer we are headed for another grand minimum.

The astronomical harmonic temperature model has been tested in its hindcast/forecast capabilities and performs quite well.

For example I calibrated the model in the period 1850-1950 and was able to reproduce all decadal multidecadal variation observed from 1950 to 2012, and vice versa. A full model that also included a possible anthropogenic component has been calibrated from 1970 to 2000 and was able to accurately forecast the temperature trend from 2000 to 2012.
About the solar harmonic model: it has been constructed by using physical information obtained in the period 1750-2010 and was able to hindcast all major solar and climatic variability observed during the Holocene (12,000 years). For example the model approximately hindcast the little ice age, medieval warm period, Dark Age cold period, roman warm period etc. The model reconstruct all secular scale oscillations observed in temperature and solar records for 2000 years at least: these include the Maunder minimum, Dalton minimum and other grand solar minima. Of course the model predicts the current warm period and a 60-year major modulation observed in the temperature since 1850. Thus the model may give some good idea about the future too. The sun is entering in a grand minimum that will reach the lowest level around in the 2030s and reach a new maximum in 2060s, the temperature will be partially regulated by this cycle. [My emphasis.]